Neoadjuvant Chemoradiation Impacts the Prognostic Effect of Surgical Margin Status in Pancreatic Adenocarcinoma

Stepwise Analysis of Resection Margin Impact on Survival and Distant Metastasis in Pancreatic Head Ductal Adenocarcinoma

The prognostic role of tumor cells in pancreatic ductal adenocarcinoma (PDAC) of the pancreatic head with direct microscopic infiltration (DMI) or in close proximity (≤1 mm) to the resection margin (RM) remains unclear. This single-center, retrospective study included specimens from 75 patients who underwent oncological resection of pancreatic head PDAC between February 2013 and July 2020. Two pathologists independently re-measured the distance between tumors and the multiple RMs. The impact of RM involvement for DMI, tumor cells within ≤1 mm, in general, and for individual RMs on overall survival (OS) and development of distant pulmonary (PM) and hepatic (HM) metastasis was analyzed. DMI of RMs was significantly associated with a shorter OS (median 5 vs 19 months, P = .02). The presence of tumor cells within ≤1 mm of RMs yielded a negative impact on OS with a trend toward significance (median 9 vs 21 months, P = .09). DMI and tumor cells within ≤1 mm of the pancreatic transection margin (PRM), individually, had a significant negative impact on OS (median 4 vs 19 months and 6 vs 19 months, P < .05), but not for any other individual RM. RM involvement of ≤1 mm of only the vascular circumferential resection margin (VCRM) resulted in a shorter time to HM development (P = 0.05). DMI of the posterior circumferential resection margin (PCRM) and VCRM, individually, showed shorter time to PM (P < .05). Potential clinical considerations include extended intraoperative evaluation of the PRM (1 mm) and intensified preoperative prediction of R1 resection as a basis for neoadjuvant therapy.

The Revised R Status is an Independent Predictor of Postresection Survival in Pancreatic Cancer After Neoadjuvant Treatment

OBJECTIVE

To investigate the oncological outcomes of patients with pancreatic ductal adenocarcinoma (PDAC) who had an R 0 or R 1 resection based on the revised R status (1 mm) after neoadjuvant therapy (NAT).

BACKGROUND

The revised R status is an independent prognostic factor in upfront-resected PDAC; however, the significance of 1 mm margin clearance after NAT remains controversial.

METHODS

Patients undergoing pancreatectomy after NAT for PDAC were identified from 2 prospectively maintained databases. Clinicopathological and survival data were analyzed. The primary outcomes were overall survival (OS), recurrence-free survival (RFS), and pattern of recurrence in association with R 0 >1 mm and R 1 ≤1 mm resections.

RESULTS

Three hundred fifty-seven patients with PDAC were included after NAT and subsequent pancreatic resection. Two hundred eight patients (58.3%) received FOLFIRINOX, 41 patients (11.5%) received gemcitabine-based regimens, and 299 individuals (83.8%) received additional radiotherapy. R 0 resections were achieved in 272 patients (76.2%) and 85 patients (23.8%) had R 1 resections. Median OS after R 0 was 41.0 months, compared with 20.6 months after R 1 resection ( P = 0.002), and even longer after additional adjuvant chemotherapy ( R 0 44.8 vs R1 20.1 months; P = 0.0032). Median RFS in the R 0 subgroup was 17.5 months versus 9.4 months in the R 1 subgroup ( P < 0.0001). R status was confirmed as an independent predictor for OS ( R 1 hazard ratio: 1.56, 95% CI: 1.07-2.26) and RFS ( R 1 hazard ratio: 1.52; 95% CI: 1.14-2.0). In addition, R 1 resections were significantly associated with local but not distant recurrence ( P < 0.0005).

CONCLUSIONS

The revised R status is an independent predictor of postresection survival and local recurrence in PDAC after NAT. Achieving R 0 resection with a margin of at least 1 mm should be a primary goal in the surgical treatment of PDAC after NAT.

Prognostic impact of resection margin status on survival after neoadjuvant treatment for pancreatic cancer: systematic review and meta-analysis

BACKGROUND

A greater than 1 mm tumour-free resection margin (R0 >1 mm) is a prognostic factor in upfront-resected pancreatic ductal adenocarcinoma. After neoadjuvant treatment (NAT); however, the prognostic impact of resection margin (R) status remains controversial.

METHODS

Randomised and non-randomised studies assessing the association of R status and survival in resected pancreatic ductal adenocarcinoma after NAT were sought by systematic searches of MEDLINE, Web of Science and CENTRAL. Hazard ratios (HR) and their corresponding 95% CI were collected to generate log HR using the inverse-variance method. Random-effects meta-analyses were performed and the results presented as weighted HR. Sensitivity and meta-regression analyses were conducted to account for different surgical procedures and varying length of follow-up, respectively.

RESULTS

Twenty-two studies with a total of 4929 patients were included. Based on univariable data, R0 greater than 1 mm was significantly associated with prolonged overall survival (OS) (HR 1.76, 95% CI 1.57-1.97; P<0.00001) and disease-free survival (DFS) (HR 1.66, 95% CI 1.39-1.97; P<0.00001). Using adjusted data, R0 greater than 1 mm was significantly associated with prolonged OS (HR 1.65, 95% CI 1.39-1.97; P<0.00001) and DFS (HR 1.76, 95% CI 1.30-2.39; P=0.0003). Results for R1 direct were comparable in the entire cohort; however, no prognostic impact was detected in sensitivity analysis including only partial pancreatoduodenectomies.

CONCLUSION

After NAT, a tumour-free margin greater than 1 mm is independently associated with improved OS as well as DFS in patients undergoing surgical resection for pancreatic cancer.

Intraoperative Pancreatic Neck Margin Assessment During Pancreaticoduodenectomy for Pancreatic Adenocarcinoma in the Era of Neoadjuvant Therapy: A Multi-institutional Analysis from the Central Pancreatic Consortium

BACKGROUND

Data regarding the survival impact of converting frozen-section (FS):R1 pancreatic neck margins to permanent section (PS):R0 by additional resection (i.e., converted-R0) during upfront pancreaticoduodenectomy for pancreatic ductal adenocarcinoma (PDAC) are conflicting. The impact of neoadjuvant therapy on this practice and its relationship with overall survival (OS) is incompletely understood.

METHODS

We reviewed PDAC patients (80% borderline resectable/locally advanced [BR/LA]) undergoing pancreaticoduodenectomy after neoadjuvant therapy at seven, academic, high-volume centers (2010-2018). Multivariable models examined the association of PS:R0, PS:R1, and converted-R0 margins with OS.

RESULTS

Of 272 patients receiving at least 2 (median 4) cycles of neoadjuvant chemotherapy (71% mFOLFIRINOX or gemcitabine/nab-paclitaxel) and undergoing pancreaticoduodenectomy with intraoperative frozen-section assessment of the transected pancreatic neck margin, PS:R0 (n = 220, 80.9%) was observed in a majority of patients; 18 patients (6.6%) had converted-R0 margins following additional resection, whereas 34 patients (12.5%) had persistently positive PS:R1 margins. At a median follow-up of 42 months, PS:R0 resection was associated with improved OS compared with either converted-R0 or PS:R1 resection (median 25 vs. 14 vs. 16 months, respectively; p = 0.023), with no survival difference between the converted-R0 and PS:R1 groups (p = 0.9). On Cox regression, SMA margin positivity (hazard ratio 2.2, p = 0.012), but not neck margin positivity (hazard ratio 1.2, p = 0.65), was associated with worse OS.

CONCLUSIONS

In this multi-institutional cohort of predominantly BR/LA PDAC patients undergoing pancreaticoduodenectomy following modern neoadjuvant therapy, pursuing a negative neck margin intraoperatively if the initial margin is positive does not appear to be associated with improved survival.

Clinical outcome comparison of laparoscopic radical antegrade modular pancreatosplenectomy vs. laparoscopic distal pancreatosplenectomy for left-sided pancreatic ductal adenocarcinoma surgical resection

Background

Laparoscopic radical antegrade modular pancreatosplenectomy (LRAMPS) is a validated surgical treatment for patients with left-sided pancreatic ductal adenocarcinoma (PDAC). In addition, laparoscopic distal pancreatectomy (LDPS) has purported benefits. However, there is a limited analysis comparing the results between LRAMPS and LDPS. Thus, this study aims to compare the short-term and long-term outcomes of patients who underwent LRAMPS and LDPS for PDAC treatment.

Methods

Patients with left-sided PDAC that underwent LRAMPS or LDPS from 2015 to 2021 were retrospectively identified. Demographic and clinic pathologic data were collected. Disease-free survival (DFS) and overall survival (OS) probabilities were obtained.

Results

The number of lymph nodes retrieved was significantly greater in the LRAMPS group than in the LDPS group. Several clinicopathological factors, including CA19-9 levels greater than 37 U/ml, positive lymph nodes, moderate to poor tumor differentiation, and peripancreas fat invasion, were associated with DFS. Moderate with poor tumor differentiation was associated with poor DFS (HR 0.568; 95% CI 0.373–0.921; P = 0.021). Levels of CA19-9 greater than 37 U/ml, CEA levels greater than 5 μg/ml, larger tumor size, positive lymph nodes, moderate with poor tumor differentiation, peripancreas fat invasion, and adjuvant chemotherapy were all associated with OS. LRAMPS nearly improved OS but did not reach statistical significance. Serum carcinoembryonic antigen (CEA) levels greater than 5 ug/ml (HR 1.693; 95% CI 1.200–1.132; P = 0.001), and positive lymph nodes (HR 2.410; 95% CI 1.453–3.995; P = 0.001) were independently associated with poor OS. Treatment with adjuvant chemotherapy was associated with improved OS (HR 0.491; 95% CI 0.248–0.708; P = 0.001).

Conclusions

The LRAMPS procedure achieved comparable results to standard LDPS in terms of postoperative outcomes. Treatment with chemotherapy is important for the prognosis of patients with left-sided pancreatic cancer.

The American Brachytherapy Society consensus statement for permanent implant brachytherapy using Yttrium-90 microsphere radioembolization for liver tumors

PURPOSE

To develop a multidisciplinary consensus for high quality multidisciplinary implementation of brachytherapy using Yttrium-90 (90Y) microspheres transarterial radioembolization (90Y TARE) for primary and metastatic cancers in the liver.

METHODS AND MATERIALS

Members of the American Brachytherapy Society (ABS) and colleagues with multidisciplinary expertise in liver tumor therapy formulated guidelines for 90Y TARE for unresectable primary liver malignancies and unresectable metastatic cancer to the liver. The consensus is provided on the most recent literature and clinical experience.

RESULTS

The ABS strongly recommends the use of 90Y microsphere brachytherapy for the definitive/palliative treatment of unresectable liver cancer when recommended by the multidisciplinary team. A quality management program must be implemented at the start of 90Y TARE program development and follow-up data should be tracked for efficacy and toxicity. Patient-specific dosimetry optimized for treatment intent is recommended when conducting 90Y TARE. Implementation in patients on systemic therapy should account for factors that may enhance treatment related toxicity without delaying treatment inappropriately. Further management and salvage therapy options including retreatment with 90Y TARE should be carefully considered.

CONCLUSIONS

ABS consensus for implementing a safe 90Y TARE program for liver cancer in the multidisciplinary setting is presented. It builds on previous guidelines to include recommendations for appropriate implementation based on current literature and practices in experienced centers. Practitioners and cooperative groups are encouraged to use this document as a guide to formulate their clinical practices and to adopt the most recent dose reporting policies that are critical for a unified outcome analysis of future effectiveness studies.

The Association Between Neoadjuvant Therapy and Pathological Outcomes in Pancreatic Cancer Patients After Resection: Prognostic Significance of Microscopic Venous Invasion

BACKGROUND

The impact of neoadjuvant therapy (NAT) on pathological outcomes, including microscopic venous invasion (MVI), remains unclear in pancreatic cancer.

METHODS

A total of 456 patients who underwent pancreatectomy for resectable and borderline resectable pancreatic cancer between July 2012 and February 2020 were retrospectively reviewed. Patients were divided into two groups: patients with NAT (n = 120, 26%) and those without NAT (n = 336, 74%). Clinicopathological factors, survival outcomes and recurrence patterns were analyzed.

RESULTS

Regarding pathological findings, the proportion of MVI was significantly lower in patients with NAT than in those without NAT (43% vs 62%, P = 0.001). The 5-year survival rate in patients with NAT was significantly better than that in those without NAT (54% vs 45%, P = 0.030). A multivariate analysis showed that MVI was an independent prognostic factor for the overall survival (OS) (hazard ratio 2.86, P = 0.003) in patients who underwent NAT. MVI was an independent risk factor for liver recurrence (odds ratio [OR] 2.38, P = 0.016) and multiple-site recurrence (OR 1.92, P = 0.027) according to a multivariate analysis. The OS in patients with liver recurrence was significantly worse than that in patients with other recurrence patterns (vs lymph node, P = 0.047; vs local, P < 0.001; vs lung, P < 0.001). The absence of NAT was a significant risk factor for MVI (OR 1.93, P = 0.007).

CONCLUSION

MVI was a crucial prognostic factor associated with liver and multiple-site recurrence in pancreatic cancer patients with NAT. MVI may be reduced by NAT, which may contribute to the improvement of survival in pancreatic cancer patients.